US lawmakers have accused Nigeria of taking a Binance Holdings Ltd. executive, Tigran Gambaryan, "hostage".
They are urging President Joe Biden to help secure his release.
Sixteen Republican congressmen including Chairman of the House Foreign Affairs Committee Michael McCaul wrote to Biden to have the case of Gambaryan referred to the Office of the Special Presidential Envoy for Hostage Affairs.
A US citizen, Gambaryan, is head of financial crime compliance at Binance and has been held in Abuja since April 2024.
Bloomberg reports that the lawmakers wrote in a June 4 letter, a copy of which it sighted, that: "The charges against Mr Gambaryan are baseless and constitute a coercion tactic by the Nigerian government to extort his employer.
"Following these charges, Mr Gambaryan qualifies as a 'U.S. Citizen wrongfully detained by a foreign government".
The face-off between Nigeria and the world's largest cryptocurrency exchange burst into view in February when Nigerian authorities detained Gambaryan and a colleague - who subsequently escaped - during a visit to discuss the company's compliance issues with the country.
"After two rounds of meetings, which were described as starting professional and then becoming increasingly hostile, the government of Nigeria took Mr. Gambaryan hostage," the lawmakers wrote.
However, Bloomberg said Nigerian Information Minister Mohammed Idris rejected the allegation that the Binance executive had been wrongfully detained.
"Nobody is being kept outside our laws and nobody's life is in danger," the media platform quoted him as saying in a telephone interview. "They have committed a crime."
Gambaryan was initially held at a guest house before formal charges were brought against him and Binance in an Abuja court in April.
He is accused alongside the company of charges including non-payment of value-added tax and corporate income tax, and complicity in aiding customers to evade taxes through its platform.
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The lawmakers said his well-being was of grave concern. He last appeared in court on May 23, but the hearing was adjourned until June 20 after his lawyer said he was too ill to proceed.
"Mr Gambaryan's health and well-being are in danger, and we fear for his life. Immediate action is essential to ensure his safety and preserve his life," the lawmakers said. The letter was also addressed to US Secretary of State Antony Blinken and Roger Carstens, special presidential envoy for hostage affairs.
